Apparatus for performing pressing operations



Nov. 6, 1928.

1,690,398 c. BOLLINGER APPARATUS FOR PERFORMING PRESSING OPERATIONSFiled May 10, 1923 2 Sheets-Sheet 1 Zia/Q7276?" C/zarlesBoZllzz erPatented Nov. 6, 1928.

UNITED STATES PATENT OFFICE.

CHARLES BOLLINGER, OF CHICAGO, ILLINOIS, ASSIG-NOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

APPARATUS FOR PERFORMING PRESSING OPERATIONS.

Application filed May 10,

This invention relates to a method of and apparatus for performingpressing opera tions and relates more particularly to such a method andapparatus which utilizes fluid under pressure as an operating medium.

An object of the invention is to provide a fluid operated pressingapparatus which is very much more rapid than apparatus of this type nowin use and one which may be operated at speeds substantially equal tothose attained by crank shaft presses. To this end a fluid actuatedpressing mechanism is provided with a mechanically actuated pump,capable of operation at high speeds, the, fluid medium being pocketedbetween the pump piston and the movable element of the pressingmechanism whereby Valves-in the pump and press are dispensed with andeach reciprocation of the pressing mechanism is directly responsive toeach reciprocation of the ump.

Another object of the invention is to provide a pressing apparatus ofthis type which is simple, involving a small number of moving parts, andone that has low initial cost and is inexpensive to maintain.

An apparatus made in accordance with the invention may comprise apressing mechanism of any suitable type having either a movable ram orcylinder operable by fluid, preferably oil or water, under pressure.Communicating with the ram is a pipe or other suitable communicatingmeans which is connected at its other end to a pressure mechanism,preferably a pump of the reciprocating type. An inert body of fluid,pref-. erably oil, is disposed within the pipe and is in contact bothwith the piston of the pump and the cylinder of the press. The pump isactuated by any suitable continuously operating means, each compressionstroke of the pump exerting pressure upon the inert body v of oil whichwill transmit the pressure applied thereto directly against the movableelement of the press, causing an actuation thereof. As the pump makesits intake stroke the pressure on the body of fluid will be relieved andthe movable element of the press may be returned to its normal positionby means of springsor othersuitable, devices.

Another object of the invention is to provide an apparatus like thatdescribed with a relief mechanism of such character that the pump orother pressure device may be ac- 1923. Serial No. 637,971.

tuated without causing an actuation of the movable element of the pressbut when it is desired to operate the said movable element it isactuated directly responsive to the pressure mechanism. With such aconstruction it is possible to have a constantly operating pump whichmay be caused to actuate the press when desired. To this end anapparatus similar to that described in the preceding paragraph may beprovided with a stand pipe or other suitable receptacle which is incommunication through a suitable valve mechanism with the pipecontaining the inert body of oil. The valve may be normally open so thatas the pump or other pressure mechanism operates, the fluid when placedunder the pressure will follow the line of least resistance and beforced into the stand pipe or other receptacle and will not exert apressure upon the movable element of the press sufiicient to cause anoperation thereof. When it is desired to cause an actuation of thepress, the said valve may be allowed to close so that the pressureapplied to the inert body of oil by the pump or other pressure mechanismwill be exerted directly upon the movable element of the press to causean actuation thereof.

Still another object of the invention is to provide a pressing mechanismof the type herein described with a safety device which will, in theevent the press is overloaded, prevent damage to the press or associatedpres sure apparatus. To this end an apparatus like that heretoforedescribed may be provided with a chamber communicating with the pipecontaining the inert body of oil. Disposed within this chamber is a.piston or other suitable device which acts against a spring or othersuitable medium which mag be so adjusted that more pressure is requireto actuate the said piston than'is required to operate the movableelement of the press. Should the press be subjected to a heavier loadthan that to which it is adjusted, as for instance should more than onethickness of the running stock be inserted between the dies of thepress, the excess pressure exerted upon the body of fluid will beabsorbed by the piston in the chamber and will not damage the operatingparts of the press, the pump, or associated apparatus.

Still another object of the invention is to provide a fluid actuatedpressing mechanism so designed that both the length, region and pressureof the stroke of its movable element ma be readily adjusted.

ther objects and advantages of the invention will more fully appear inthe following description and will be particularly pointed out in theappended claims.

The expressions pressing operations, press, and pressing mechanism usedin the specification and claims are intended to define and includevarious other operations and mechanisms of this general nature, such asstamping operations, stamping presses,

punching operations, punch presses, shearing operations, shearingmachines, printing operations, printing presses, embossing operations,embossing presses, forging operations, forging presses, etc.

In the accompanying drawings,

Fig. 1 is a front elevation of an apparatus showing one embodiment ofthe invention;

Fig. 2 is afragmentary schematic view in vertical section of themechanism shown in Fig. 1;

Fig. 3 is a fragmentary enlarged detailed view in front elevationshowing the devices for operatin the relief mechanism;

Fig. 4 is a fragmentary side elevation of the safety mechanism; 1

Fig. 5 is a horizontal sectional view taken on the line 5-5 of Fig. 3,and

Fig. 6 is a horizontal sectional view taken on the line 66 of Fig. 3.

Referring now to the drawings in detail in which like reference numeralsdesignate similar parts throughout the several views. 10 represents apressing mechanism of the fluid actuated type.

This mechanism comprises essentially a fixed ram 11 and a cylinder 12which is vertically movable within suitable gibs or guideways 13 and hasattached to its lower end the punch or male die 14, co-operating withwhich is a female die 15, supported by the bed plate 16 of the press,Figs. 1 and 2. Connected to the cylinder 12 are rods 17 which projectthrough openings made in a plate 18 supported by the framework of thepress. Compression springs 19 are mounted on the rods 17 and when thecylinder moves downwardly these springs are compressed between the plate18 and washers 21 mounted on the rods 17 and held in place by nuts 22.The springs 19 serve to normally hold the cylinder at the limit of itsupward stroke as shown in Fig. 2 and provide a means for returning thecylinder after each downward stroke thereof.

The ram 11 is provided with a central passageway 23 communicating withone end of a tu e 24 which is connected with a pipe 25. This pipe is incommunication with the cylinder 26 of a pump 27 which is-of thereciproeating type. The passageway 23 constitutes the inlet and outletfor the cylinder of the press, while the pipe 25 constitutes a commoninlet and outlet for the cylinder 26 of the pump 27, Fig. 2. The piston28 of the pump is actuated through the usual pitman 29, crank shaft 30,and pulley 31, which is driven by a belt 32 connected with any suitablesource of ower (not shown), Fig. 1.

(gonnecting with the pipes 24 and 25 is a pipe 33 which may be throwninto and out of communication with a stand pipe 34, by means of a valve35. The upper end of the stand ppe 34 is open to the air. Thisconstruction comprises a relief device, the purpose and operation ofwhich will be herein after described.

Also in communication with the pipe 24 is a cylinder 36 containing apiston 37 having a connecting rod 38 to which a verticaly reciprocablehead 39 is attached. Connected to the head 39 are rods 40 verticallymovable through a plate 41. Mounted upon the rods 40 are compressionsprings 42 which are strained between the plate 41 and washers 43mounted on the rods 41 and held in place by nuts 44. The springs 42serve to normally hold the reciprocable head 39 and piston 37 in theiruppermost positions as shown in Fig. 2. This mechanism comprises asafety device, the purpose and operation of which will be hereinafterdescribed.

Connected with the valve 35 is a valve stem 45, Figs. 2 and 3, uponwhich a spacing tube 47 is disposed which extends between the valvecasing and a washer 46. Encircling the valve stem 45 is a coil spring 48positioned between the washer 46 and a washer 49 which engages atransverse pin 50 secured in the valve stem, this pin resting normallyupon the forked portion 51 of an arm 52, Figs. 3 and 6. This arm isnormally held in the position shown in Fig. 3 by means of a coil spring53 also encircling the valve stem 45 and strained between the forkedportion of the arm 52 and a tubular boss 54 formed on the.

pump cylinder 26 constituting a bearing for the valve stem 45. With theparts in their position as shown in Fig. 3, the spring 53 and arm 52serve to hold the valve stem in its uppermost position in which thevalve 35 is open, establishing communication between the stand pipe 34and the pipes 33, 24, and 25. The arm 52 is pivotally mounted at one endupon a standard 55 attached to the pump cylinder and at its other end ispivotally con- III! nected with a link 56, Figs. 1 and 3. This link ispivoted at its lower end to an arm 57 pivoted at a point 58 to theframework of the pump and connected with a leverage system indicated bythe reference number 58. The leverage system 58 is connected with a foottreadle 59 in such manner that a depression of the foot treadle causesthe arm 57 to be rotated clockwise about its pivot 58, causing adownward movement of the link 56 and arm 52 against the action of thespring 53. A downward movement of the arm 52 permits the spring 48 toexpand and move the valve stem 45 downwardly a distance suflicient toclose the valve 35, provided the lower end of the valve stem is notblocked by a trigger 60 in the manner shown in Fig. 3. This triggeris'normally held in' a vertical position by means of a. spring 61 whichholds the said trigger against an adjustable stop 62. The trigger 60 isfastened upon a shaft 63 to which is also secured a rocker arm 64. Thisrocker arm is so positioned as to be engaged by a push rod 65 actuatedby the crank shaft 30 of the pump. l/Vhen the piston of the pump is inits lowermost position, the push rod 65 will have been moved upwardly adistance sufficient to engage the rocker arm 64 and rotate it clockwise.This movement of the rocker arm 64 causes a clockwise rotation of thetrip 60 a distance suflicient to move it from beneath the lower end ofthe valve stem 45 and thereby permit the said valve stem to be moveddownwardly under the action of the spring 48 to .close the valve 35 aspreviously described. Since the trip 60 is actuated by the push rod 65it will be understood that the valve 35 can only be closed at a timewhen the piston 28 of the pump 26 is at the limit of its downwardstroke, at which time the pump is prepared to make a completecompression stroke and thereby cause its maximum displacement.

A body of fluid 70, preferably oil, is disposed within the cylinders 12,36, and 26, and pipes 24, 25, 33, and 34 as shown in Fig. 2. This fluidbody normally has the level indicated by the dotted line A.

The drawings illustrate the various parts of the mechanism in theirunopera-ted positions. l/Vhen it is desired to operate the press 10, thepump 27 is first set in motion by means of the source of power connectedwith the belt 32. Each upward movement of the piston 28 of the pump 27will displace a portion of the oil 70, but since the valve 35 is open,the displaced oil will be forced into the stand pipe 34, lifting thelevel of the oil y from the dotted line position A to the dotted lineposition B. Since the displaced oil is forced into the stand pipe itwill cause no actuation of the press cylinder 12. Each downward movementof the piston 28 will lower the level of the oil 70 in the stand pipeback to its normal level as indicated by dotted line A. \Vhen it isdesired to cause an-actuation of the press cylinder 12 the foo-t treadle59 is depressed which, through the leverage system previously described,will cause the arm 52 to be moved downwardly so that as soon as thepiston 28 of the pump 27 is at the limit of its downward movement, thepush rod 65, will through the rocker arm 64, move the trip 60 out of thepath of the valve stem 45 and permit the said stem to be moveddownwardly under the action of the spring 48 to close the valve 35. Asthe piston 26 moves upwardly it will exert pressure on the oil 70 in thepipes 25, 33, and 24. The oil will transmit the pressure applied by thepiston 28 directly against the cylinder 12 cansing it to be moveddownwardly and perform a pressing operation. As the piston 28 of thepump 27 makes its downward stroke, the oil fed into the cylinder 12 willbe withdrawn therefrom'and the said cylinder returned to its normalposition by means of the springs 19. As long as the foot treadle isdepressed the valve 35 will be closed at each down stroke of the piston28 of the pump and at each upward stroke of said piston the presscylinder 12 will be actuated.

It is essential that the pump 27 displace an amount of the oil 70sufficient to actuate the press cylinder 12 for performing a nor-.

mal punching operation. Rather than ad just-the pump so that it willaccurately displace exactly the amount of oil required for a pressingoperation and no more, it has been found desirable to provide a pumpwhich will displace more oil than that necessaryto perform a normalpressing operation, and then provide a mechanism which will absorb thesurplus oil displaced by the pump. In the present apparatus thismechanism comprises the piston 37 mounted within the cylinder 36, thepiston being held in its uppermost position by means of the springs 42.The force of these springs is so adjusted that they exert a pressureupon the piston 37 slightly greater than the pressure necessary toperform the normal pressing operation. As a consequence all excessdisplacement caused by the pump over and above that necessary to performa pressing operation will be absorbed by the piston 37 and will not beexerted against the pump cylinder. By adjusting the force of the springs42 the amount of resistance offered by the piston 37 may be adjustedwhich will control the amount of pressure exerted on the work by thecylinder 12 of the press. This mechanism also constitutes a safetydevice should the press be abnormally overloaded, due to the insertionof too heavy stock between the dies of the press, or to other causeswhich would shorten the normal stroke of the press and tend to exertdamaging strains 1 therein, the excess oil 70 displaced occasioned bythe shortened stroke of the press being absorbed by the piston 37.

Means is provided for adjusting both the length and region of the strokeof the cylinder 12. This means comprises a plurality of adjustable stops7 0 attached to the bolster plate 16 and sleeves 71 surrounding each ofthe rods 17, these sleeves having collars 72 threaded thereon. Byadjusting the collars 72 the limit of the upward stroke of the cylin-.der may be lengthened or shortened, and by adjusting the stops 7 O thedownward movement of the said cylinder may be made longer or shorter. Byadjusting the collars 72 a greater distance. than the stops or viceversa, the stroke of the cylinder may be lengthened or shortened. If thecollars 72 and stops 70 are both adjusted equal distances, the length ofthe stroke of the cylinder 12 is maintained the same, but the region ofits stroke is either raised or lowered, dependent upon the manner inwhich the said collars and stops are adjusted.

lVhat is claimed is:

1. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a valveless pressure mechinism, abody of fluid connecting said movable element and said pressuremechanism, said pressure mechanism operable throughout its effectivecompressing stroke to produce a working pressure upon the movableelement and capable of supplying a pressure in excess of that requiredto complete the pressing operation of the movable element, and meansassociated with said fluid and operable independently thereof tocounteract the development of pressure by said pressure mechanism.

2. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a pressure mechanism, a

body offluid connecting said movable element and said pressuremechanism, and means associated with said fluid and operableindependently thereof to counteract the develop ment of pressure by saidpressure mechanism, said means being controlled by said pressuremechanism.

3. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a reciprocating valveless pump, apipe connecting said movable element with the piston of said pump, achamber communicating with said pipe, fluid within said pipe, the pumpbeing operable throughout its effective compressing stroke to produce aworking pressure upon the movable element and capable of supplying apressure in excess of that required to complete the pressing operationof the movable element, a valve mechanism adapted to open or closecommunication between said chamber and said pipe, means for actuatingsaid valve, and means for operating said pump.

4. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a valveless reciprocating pump, apipe connecting said movable element with the piston of said pump, achamber communicating with said pipe, fluid within said pipe, the pumpbeing operable throughout its effective compressing stroke to produce aworking pressure upon'the movable element and capable of supplying apressure in excess of that required to complete the pressing operationof the movable element, a valve mechanism adapted to open and closecommunication between said chamber and said pipe, means for normallyholding said valve open, means for closing said valve, and means foroperating said pump.

5. In an apparatus for performing pressing operations, comprising apressing mechanism having a movable element, a valveless pressuremechanism, a body of fluid connecting said movable element and saidpressure mechanism, said pressuremechanism operable throughout itseffective compressing stroke to produce a working pressure upon themovable element and capable of supplying a pressure in excess of thatrequired to complete the pressing operation of the movable element, anda chamber associated with said fluid adapted when open to counteract thedevelopment of pressure by said pressure mechanism.

6. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a valveless reciprocating pump, apipeconnecting said movable element with the piston of said pump, meansfor retaining said movable element normally in an unoperated position, achamber communieating with said pipe, fluid Within said pipe, the pumpbeing operable throughout its cflectivecompressing stroke to produce aworking pressure upon the movable element and capable of supplying apressure in excess of that required to complete the pressing operationof the movable element, a valve mechanism adapted to open and closecommunication between said chamber and said pipe, means for normallyholding said valve open, independent means for closing said valve, andmeans for operating said pump.

7. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a valveless pressure mechanism, abody of fluid associated with the movable element and with said pressuremechanism, said pressure mechanism operable throughout its effectivecompressing stroke to produce a working pressure upon the movableelement and capable of supplying a pressure in excess of that requiredto complete the pressing operation of said movable element, mechanismoperable to counteract the development of excess pressure by saidpressure mechanism, and means associated with said fluid operable tocounteract the development of substantially all pressure by saidpressure mechanism.

8. In an apparatus for performing pressing operations, a mechanismhaving a movable element, a pressure mechanism, a pipe connecting saidmovable element with said pressure mechanism, a chamber communieatingwith said pipe, fluid within said pipe, a valve mechanism adapted toopen and close communication between said chamber and saidpipe,rmeansfor normally holding said valve open, means for closing saidvalve, and mechanism controlled by said pressure mechanism forpreventing an operation of said valve closing means until said pressuremechanism is prepared to cause its maximum displacement of the fluid,and means for operatin g said pressure mechanism.

9. An apparatus for performing pressing operations, comprising mechanismhaving a movable element, pressure mechanism, a body of fluid associatedwith said movable element and said pressure mechanism, relieving meansassociated with said fluid and operable independently thereof normallyto counteract the developmentof substantially all pressure by saidpressure mechanism, and means controlled by said pressure mechanism forpreventing the operation of said relieving means during the actuation ofthe movable element.

10. An apparatus for performing pressing operations, comprisingmechanism having a movable element, pressure mechanism, a body of fluidassociated with said movable element and said pressure mechanism,relieving means associated with said fluid operable normally tocounteract the development of substantially all the pressure by saidpressure mechanism, means for preventing the operation of said relievingmeans, and devices controlled by said pressure mechanism for permittingthe operation of said preventing means only when said pressure mechanismis prepared to cause its maximum displacement of the fluid.

11. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a pressure mechanism, a body offluid connecting said movable element and said pressure mechanism,relieving means associated with said fluid operable to counteract thedevelopment of pressure by said pressure mechanism, and mechanism forpermitting an operation of said means only when said pressure mechanismis prepared to cause its maximum displacement.

12. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, pressure mechanism, a body of fluidconnecting said movable element and said pressure mechanism, relievingmeans associated with said fluid operable to counteract the developmentof pressure by said pressure mechanism, mechanism for permitting anoperation of said means only when said pressure mechanism is prepared tocause its maximum displacement, said means being 14. In an apparatus forperformlng pressing operations, a pressing mechanism having a movableelement, a valveless reciprocating pump, a body of fluid connecting saidmovable element with said pump in such manner that each actuation ofsaid movable element is directly responsive to each actuation of saidpump, and means associated with said fluid and operable independentlythereof to counteract the development of pressure by said pump, saidmeans being controlled by said pump.

15. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a pressure mechanism, a body offluid associated with said movable element and with said pressuremechanism in such manner that each actuation of said movable element isdirectly responsive to each actuation of said pressure mechanism, saidpressure mechanism operable throughout its eflective compressing stroketo produce a working pressure upon the movable element .and capable ofsupplying a pressure in excess of that required to complete the pressingoperation of said movable element, mech-' anism operable to counteractthe develop ment of excess pressure by said pressure mechanism, andmeans associated with said fluid operable to counteract the developmentof substantially all pressure by said pressure mechanism.

16. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a valveless reciprocating pump, abody of fluid connecting said movable element and said pump, meansassociated with said fluid operable independently thereof to counteractthe development of pressure'by said pump, and mechanism for permittingan operation of saidv means only when said pump is prepared to cause itsmaximum displacement.

17. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a pressure mechanism, a body offluid connecting said movable element and said pressure mechanism insuch manner that each. actuation of said movable element is directlyresponsive to each actuation of said pressure mechanism, meansassociated with said fluid operable to counteract the development ofpressure by said pressure mechanism, and mechanism for permittin anoperation of said means only when sai pressure mechanism is prepared tocause its maximum displacement.

18. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a pressure mechanism, a body offluid connecting said movable'element and said pressure mechanism insuch manner that each actuation of said movable element is directlyresponsive to each actuathe development of pressure by said pressuremechanism, and mechanism for permitting an operation of said means onlywhen said pressure mechanism is prepared to cause its 8 maximumdisplacement, said means being controlled by said pressure mechanism.

19. In an apparatus for performing pressing operations, a pressingmechanism having a movable element, a valveless reciprocating pump, abody of fluid connecting said movable element and said pump, meansassociated with said fluid operable to counteract the development ofpressure by said pump, and mechanism for permitting an operation of saidmeans only when said pump is prepared to cause its maximum displacement,said means being controlled by said pump.

In witness whereof, I hereunto subscribe my name this 1st day of May, A.D., 1923.

CHARLES BOLLINGER.

